From a reliable source, the maximum capacity of a standard bus used as school bus is 72 students. Because the bus that Mr. Tuttle drives is already 3/4 full, only 1/4 of the capacity is unoccupied. With this, the number of the empty seats is calculated by multiplying 72 by 1/4 as shown below.
empty seats = (1/4)(72) = 18
Therefore, the bus could have accommodated 18 more students.
To solve this, you need to subtract 180 from 400: (400-180=220). After that (I used the fraction/proportion/variable way, but there are others), so 220/400=%(p)/100. Multiply diaganolly, so 400*p=400p, which is equal to 220*100=22000. Therefore, 400p=22000. Now, you have to isolate the variable by dividing both sides by 400: 400p/400=p, and 22000/400=55. Therefore, p=55, or %=55, so the answer is 55%, or C.
